AICME II abstracts

Pattern and process in terrestrial plant communities: ...

Pattern and process in terrestrial plant communities: ...

AICME II abstracts

and discuss challenges for the development of predictive and explanatory models of vegetation dynamics for the Mediterranean region.

Coexistence of functional-types in Mediterranean forests: computational approximations and analytical solutions M. A. Zavala

1

, O. Arino2 and R. Bravo de la Parra3 .

A major challenge for ecology is to explain the ecological processes generating and maintaining observed patterns in plant community structure and dynamics. Simulation models that connect species individual ecological strategies to stand resource heterogeneity have been shown useful approximations to identify assembly rules of forest ecosystems (1), (2). Forest simulators allow us to incorporate a great deal of biological detail including specific parameters to describe species individual ecological strategies, as well as tree population size-structure. The mathematical tractability of these simulators however, remains rather limited, which seriously restricts the biological interpretability of simulation results. In this presentation we present a size-structured mechanistic simulator that incorporates critical ecological processes for Mediterranean forests such as competition for light and water resources and that is based on functionaltypes rather than on individual species. Secondly we introduce an analyt ical model of stand dynamics that preserves essential features of the forest simulator such as size structure and one-sided light competition. We show the existence of a stable steady state solution for a wide range of biologically realistic parameter values. Finally we compare advantages and caveats of our simulation and analytical framework with respect to simpler species-based models of tree coexistence developed for these forests

References [1] 1988. Tilman, D. Plant strategies and the dynamics and structure of plant communities. Princeton University Press, Princeton, New Jersey. [2] 1996. Pacala, S.W., C.D. Canham, J. Saponara, J.A. Silander, R.K. Kobe and E. Ribbens. Forest models defined by field measurements: estimation, error analysis and dynamics. Ecological Monographs 66: 1-43.

1

Departamento de Ecolog´ıa, Facultad de Ciencias, Universidad de Alcal´ a, 28871, Alcal´ a (Madrid), (e-mail: [email protected]). 2 I.R.D., 32 avenue Henri Varagnat 93143 Bondy, France (e-mail: [email protected]). 3 Departamento de Matem´ aticas, Facultad de Ciencias, Universidad de Alcal´ a, 28871, Alcal´ a (Madrid), Spain (e-mail: [email protected]).

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